SQL/MX 3.2.1 Reference Manual (H06.26+, J06.15+)

MXCI Commands
HP NonStop SQL/MX Release 3.2.1 Reference Manual—691117-004
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Considerations for SHOWDDL
Considerations for SHOWDDL
•
SHOWDDL cannot accurately replicate the original creation text for an object.
For ways in which the output of SHOWDDL can differ from the original DDL used
to create an object, see Differences Between SHOWDDL Output and Original DDL
on page 4-85.
•
SHOWDDL will start a TMF transaction if one is not present. Ensure that TMF is
running for SHOWDDL to start the transaction.
•
SHOWDDL output is in the English (ISO88591) character set.
•
When used on an SQL/MP table through an SQL/MP alias, SHOWDDL displays
the DDL of the SQL/MP table using equivalent SQL/MX syntax.
•
SHOWDDL can display referential integrity actions. If the referential integrity action
is NO ACTION, then it is not displayed in the output.
•
The SHOWDDL DEPENDENT option is not supported for views and triggers.
•
The SHOWDDL output shows if the view Similarity Check option is enabled or
disabled for views.
•
Starting with SQL/MX Release 3.2.1, SHOWDDL displays the DDL syntax for
sequence generators. SHOWDDL also displays the Guardian file location of
SG_TABLE associated with the sequence generator.
•
SHOWDDL will display the following attributes for the IDENTITY column:
•
Default specification of the IDENTITY column
•
Internal Sequence Generator attributes
•
Location of the SG Table
Differences Between SHOWDDL Output and Original DDL
•
SHOWDDL displays SQL/MX system-created indexes as user-created indexes. In
the output of SHOWDDL, each system-created index is preceded by the comment
'--The following index is a system-created index--'. Because
you cannot explicitly create a system-created index, feeding the output of a
system-created index back into MXCI results in a user-created index.
•
All column constraints (NOT NULL, UNIQUE, PRIMARY KEY, CHECK,
REFERENCES) are transformed into table constraints. For NOT NULL constraints,
“NOT NULL [NOT DROPPABLE]” is included in the column definitions but is
commented out. All NOT NULL NOT DROPPABLE constraints are consolidated
into a single check constraint, while NOT NULL DROPPABLE column constraints
remain in separate check constraints.
•
Each droppable constraint that creates an index (droppable primary key and
unique constraints) is moved out of the CREATE TABLE statement and